Washer 4×12 aisi 316 – code: a4-9021a-04×012 – Osculati

Flat washer 4×12 in AISI 316 stainless steel Osculati

The washer 4×12 in AISI 316 Osculati (supplier code a4-9021a-04×012) is a hardware component designed to properly and neatly complete fastening with screw and nut, especially when a wider support surface than a standard washer is needed. In nautical and onboard plant engineering, the flat washer is often a decisive detail: it helps to distribute the tightening load, a protect the surface of the component being worked on and to make the assembly more stable over time, reducing the risk of marking or deforming more delicate materials.

This washer belongs to the family of flat washers “three times the hole width”, a typical choice when a wider support is desired. It is recommended both as replacement interventions maintenance and restoration of stainless steel hardware, with easy identification thanks to nominal size and product code.

Product features and details

Type: “wide” flat washer”

The washer is a flat washer with enlarged support imprint (category “three times the hole width”). In practice, compared to a standard washer, it offers a larger contact surface between the fastening element (screw/nut) and the component, being useful when:

• you want increasing the support area to better distribute pressure;
• you want to protect the surface of the tightened piece (for example on sheets, brackets, supports or components with finish);
• working on materials that can be more easily marked or on holes with tolerances that require a more generous support.

Material: stainless steel AISI 316

The declared material is AISI 316 stainless steel, commonly chosen in nautical and plant engineering contexts where stainless steel hardware suitable for typical onboard usage conditions is sought. The use of stainless steel allows maintaining consistency with bolts and accessories in stainless steel, simplifying spare parts management and maintenance.

Nominal size 4×12

The washer is identified as 4×12. This indication is normally used to quickly recognize the nominal size during selection, especially when existing fastenings need to be restored or hardware standardized on a system.

Product and supplier code

• Supplier: Osculati S.r.l.
• Supplier product code: a4-9021a-04×012

For repeated purchases, inventory management or quick replacements, the code is the most reliable reference to exactly identify the item, avoiding ambiguity between similar variants.

The cable gland is suitable for installations where cables must pass through a surface (for example, a deck or a bulkhead) and a dedicated, neater, and more finished solution is desired compared to an improvised passage.

This stainless steel flat washer is suitable for multiple applications of fastening and assembly where it is useful to insert a support element between screw/nut and component. In particular, in the nautical field it can be used in maintenance and assembly activities on:

• onboard hardware and accessories installed on supports or brackets;
• plant engineering and technical components where a more uniform distribution of tightening is desired;
• assemblies with bearing surfaces that you want to protect from marks or nut imprints;
• restoration of existing fastenings when you want to switch to a washer with wider support.

Choosing a “wide” washer is particularly practical when the component to be tightened has a relatively thin surface or when you prefer to increase the contact area without modifying the rest of the bolting.

Usage and operational notes

Matching with screw and nut

The flat washer is normally placed between the screw head (or nut) and the component surface. In specific assemblies, it can also be used in combination with other fastening elements, depending on assembly needs and maintenance practices adopted.

Correct size selection

For a correct choice, it is advisable to check dimensional compatibility with the bolting in use and with the component hole. When working on existing systems, the nominal size and product code are the most practical references to replicate the original configuration or to switch to a washer with wider support.

Good maintenance practices

• Use stainless steel washers consistent with the other stainless steel small parts present in the assembly.
• Check the condition of the washer during disassembly and reassembly: if deformed or marked, consider replacing it.
• In case of doubts about the choice of washer (standard vs wide), consider the need for support and the surface to be protected.

This Osculati washer is a simple but important solution for those who want a tidier fastening and a more rational management of spare parts in the nautical and plant engineering fields.

FAQ – Frequently Asked Questions

What kind of washer is this 4×12 Osculati?

It is a flat washer in AISI 316 stainless steel belonging to the family of “three times hole width” washers, designed to offer a wider support than a standard washer.

What is a “wide” flat washer used for?

It serves to distribute the clamping load over a larger surface and to protect the support surface between screw/nut and component, being useful in many assemblies and maintenance interventions.

What is the product code to identify this spare part?

The supplier product code is a4-9021a-04×012. It is the recommended reference for reorders and to avoid confusion with similar variants.

In which contexts is this AISI 316 washer recommended?

It is recommended for fastening and assembly in nautical and onboard plant engineering, where stainless steel hardware is commonly used and a wider support surface is desired.

How do I choose the correct size of the washer?

It is advisable to check the nominal size (4×12) and compare it with the bolts and the hole of the component being worked on. In case of replacement, size and product code help to replicate the existing installation.